Techniques for hydraulically fracturing subterranean formations by injecting a fracturing fluid down a well and into the formation under sufficient pressure to create fractures in a formation are well known. Proppant materials are generally entrained in the fracturing fluid and are deposited in the fracture to keep the fracture open.
After fracturing the formation, hydrocarbonaceous fluids are produced from the formation into the well. These produced fluids may carry sand entrained therein, particularly when the subsurface formation is an unconsolidated formation. Produced sand is undesirable form any reasons. It is abrasive to components found within the well, such as tubing, pumps and valves, and must be removed from the produced fluids at the surface. Further, produced sand may partially or completely clog the well, substantially inhibiting production, thereby making necessary an expensive workover. In addition, sand flowing from the subsurface formation may leave therein a cavity which may result in caving of the formation and collapse of a well casing.
Often after completion of hydraulic fracturing, a steam-flood or other heat generating method is used to heat the formation to remove hydrocarbonaceous fluids therefrom after having placed a proppant into the created fractures. Proppants utilized in this manner keep the created fractures from closing. They also assist in reducing undesired fines from being carried from the formation with the produced fluids. Also, proppants increase the permeability thereby allowing more intimate contact of the heating medium with the formation. Generally sand is used as a proppant. However, use of sand affords only a sufficient degree of heat conductivity.
Therefore, what is needed is a method for fracturing a formation wherein a proppant is utilized, which proppant, in addition to holding open the fractures created, also allows for greater heat conductivity into the formation so as to allow increased amounts of hydrocarbonaceous fluids to be removed from the formation.